BACKGROUND

The invention relates to a handling system, a vessel, in particular a cable barge, and a method for handling a long-length cable on said vessel .

Long length cables, e.g. for use as electrical infrastructure in an offshore wind farm, are typically shipped from a factory located at a sea port by a Cable Laying Vessel or CLV. On a CLV, cables are stored on large rotating turn tables. Said cables may be conveniently manufactured at or near said sea port and loaded directly into the CLV. However, sometimes, the cables are manufactured at an inland factory and have to be transported first to the sea port via the waterways. When transporting from inland factories, the cable is wound on a reel, which is limited in size because of the width of the locks and the height of the bridges along the waterways. Hence, the length of the cable that can be transported is limited.

WO 2010/121781 A2 discloses an assembly of a plurality of winding drums for storing a long length of an electrical cable on a vessel. The winding drums are arranged coaxially in a straight line, one behind the other. The winding drums have drum discs that are provided with openings so that the drum discs can be bridged. Hence, the cable can be wound onto one of the winding drums until it is full, after which the cable is fed onto one of the adjacent winding drums to continue the winding. The assembly of winding drums allows for more length of continuous cable to be transported on a single vessel without increasing the size of the winding drums. However, the assembly is rather complex in use.

It is an object of the present invention to provide a handling system, a vessel and a method for handling a long length cable on said vessel .

SUMMARY OF THE INVENTION

According to a first aspect, the invention provides a handling system for handling a long-length cable on a vessel, wherein the vessel comprises a hull with a bow, a stern and a port side and a starboard side extending in a longitudinal direction between the bow and the stern, wherein the hull defines an elongated storage compartment, wherein the handling system comprises an input member for receiving the long-length cable onto the vessel and for feeding the long-length cable into the storage compartment in a feeding direction at an input position, wherein the handling system further comprises a laying device that is movable along a loop-shaped laying path through the storage compartment in a first laying direction parallel to the longitudinal direction along the port side and in a second laying direction opposite to the first laying direction along the starboard side, wherein the laying device comprises an output member that is arranged for laying the long-length cable inside the storage compartment at an output position that moves along said loop-shaped laying path when the laying device is moved, wherein the handling system further comprises a first cable guide for accumulating a length of the long-length cable between the input position and the output position, wherein the first cable guide is arranged for guiding said accumulated length of the long-length cable along a first guide path that is variable in shape to keep the length of the long-length cable between the input position and the output position constant or substantially constant.

By keeping the accumulated length of the long- length cable constant, the laying device can be moved in both laying directions along the loop-shaped laying path while the long-length cable can be fed continuously through the input member in the feeding direction into the storage compartment. The long-length cable can thus be continuously moved at a constant speed, even though the laying device moves in an opposite direction to the feeding direction for at least a part of the loop-shaped laying path. By allowing the laying device to move in the longitudinal direction of the vessel, large lengths of the long-length cable can be laid down with each winding, thereby increasing the capacity of the vessel.

In an embodiment thereof the first cable guide is arranged for doubling back at least a part of the accumulated length of the long-length cable in a return direction opposite to the feeding direction when the laying device is upstream of the input position in the feeding direction. Hence, the doubled-back part of the accumulated length of the long-length cable can effectively keep the overall length of the accumulated length of the long-length cable constant, even if the laying device is moving upstream of the input position.

In a further embodiment thereof the first cable guide comprises a plurality of interlinked segments that are movable with respect to each other to define the first guide path. Said interlinked segments can effectively guide the long-length cable while providing the first cable guide with the freedom of movement to keep the accumulated length constant and simultaneously allowing the long-length cable to be continuously fed through said first cable guide.

Preferably, the first cable guide is a cable carrier, preferably a chain-style cable carrier. Such a cable carrier can effectively guide the long-length cable while providing the first cable guide with the freedom of movement to keep the accumulated length constant.

In a further embodiment the feeding direction is parallel or substantially parallel to the longitudinal direction. Hence, input member and the first cable guide are all arranged to function in the longitudinal direction of the vessel.

In a further embodiment the input position is half-way along the loop-shaped laying path in the feeding direction. This ensures that the part of the accumulated length of the long-length cable that can be doubled-back in the return direction opposite to the feeding direction is sufficient to reach the opposite end of the loop-shaped laying path.

In a further embodiment the first cable guide is arranged for forming a first variably arcuate section in the first guide path that is arranged for directing the long-length cable from the feeding direction into a first guide direction towards the laying device. Hence, the long- length cable can be deflected away from the feeding direction towards the laying device.

In an embodiment thereof the laying device is arranged for receiving the long-length cable from the first cable guide in a second guide direction, wherein the first cable guide is arranged for forming a second variably arcuate section in the first guide path that is arranged for directing the long-length cable from the first guide direction into said second guide direction. By providing the second variably arcuate section, the first guide path can be made to more accurately meet the direction in which the long-length cable is received into the laying device.

In an embodiment thereof the second guide direction is directed away from the output member, wherein the laying device comprises a second cable guide for guiding the long-length cable along a second guide path from the second guide direction into a third guide direction towards the output member. By initially directing the long-length cable away from the output member, the second guide path can be chosen to have a larger radius between the second guide direction and the third guide direction so that the minimum bending radius of the long- length cable is not exceeded.

In an embodiment thereof the laying device is arranged to extend upright or vertical from the storage compartment, wherein the second guide direction is upwards and the third guide direction is downwards. Hence, the bend in the long-length cable in the second cable guide can be made in a vertical direction above the vessel.

In an embodiment thereof the second guide path comprises a freefall section directly upstream of the output member in which the second guide path extends vertical or substantially vertical. The freefall section allows the long-length cable to relax tension, e.g. torsion and/or twists prior to the laying at the output position.

In a further embodiment thereof the second cable guide comprises a plurality of interlinked segments that are movable with respect to each other to define the second guide path. Said interlinked segments can effectively guide the long-length cable while simultaneously allowing the long-length cable to continuously fed through said second cable guide.

In a further embodiment the laying device comprises a base and a head that is rotatable with respect to said base about an upright or vertical rotation axis, wherein the output member is provided to and rotatable together with the head, wherein the head is arranged to be rotated when transitioning from the first laying direction to the second laying direction and when transitioning from the second laying direction to the first laying direction. Hence, the head can follow the loop-shaped guide path while the output member lays the long-length cable along said loop-shaped guide path.

In an embodiment thereof the head is liftable with respect to the base in a lifting direction parallel to the upright or vertical rotation axis. By lifting the head, several layers of side-by-side windings of the long-length cable can be stacked on top of each other inside the storage chamber, thereby increasing the capacity of the vessel .

In a further embodiment thereof the output member is provided with a laying arm with an output nozzle at the distal end thereof to lay the long-length cable into the storage compartment along the loop-shaped laying path, wherein the laying arm is swivable about a laying axis for laterally adjusting the output position with respect to the loop-shape laying path with each winding of the long-length cable. Said laying arm can be used to consecutive windings of the same long-length cable side-by-side in said lateral direction to form a layer of side-by-side windings.

In a further embodiment thereof the head is foldable with respect to the base about a horizontal folding axis from an active upright position into an inactive transport position. The head can be folded into the inactive transport position to reduce the height of the handling system on the vessel, so that the vessel can pass more easily under some bridges.

In a further embodiment the laying device is arranged to be moved along the loop-shaped laying path at a laying speed, wherein the laying device comprises a pulling member for pulling the long-length cable through the laying device towards the output member at a pulling speed, wherein the handling system comprises a control unit for controlling the pulling speed of the pulling member with respect to the laying speed of the laying device. This allows for controlling the behavior of the long-length cable during the laying. In particular, it has proven to be advantageous when the control unit is arranged for controlling the pulling speed to a speed smaller than the laying speed during inside-out laying of the long-length cable to pull consecutive windings of the long-length cable tightly against each other. Additionally or alternatively, it has proven advantageous when the control unit is arranged for controlling the pulling speed to a speed larger than the laying speed during outside-in laying of the long-length cable to push consecutive windings of the long-length cable tightly against each other. By pulling and pushing the long-length cable during inside-out and outside-in laying, respectively, more windings of the long- length cable can be fitted in the same area of the storage compartment .

In a further embodiment the input member comprises a beam that is arranged to be placed at the bow or the stern of the vessel and that is arranged to be swivable about an upright or vertical swivel axis between a first loading orientation parallel to the feeding direction, a second loading orientation transverse and/or perpendicular to the feeding direction and any loading orientation therein between. The loading orientation can be chosen conveniently. The first loading orientation may for instance be used for loading or unloading in line with the feeding direction, e.g. to another vessel or when the draught of the fully loaded vessel makes it impossible to deliver the long-length cable directly onto the quay. The second loading orientation can be used to load or unload the long-length cable directly onto the quay.

In a further embodiment the long-length cable is fed onto the vessel via the input member at an input speed, wherein the input member comprises a dancer roller for measuring said input speed. The dancer roller allows for keeping the tension in the long-length cable constant, despite changes in the input speed. Moreover, by measuring the position of the dancer roller, a signal indicative of the input speed can be obtained, which can be used by the handling system to optimize the loading and/or unloading of the long-length cable.

In a further embodiment the output member of the laying device is arranged for pulling the long-length cable out of the storage compartment and wherein the input member is arranged for paying out the long-length cable during an unloading mode of the handling system. The handling system has been described above in relation to the loading process. It will however be apparent to one skilled in the art that unloading merely involves using the handling system in reverse order.

According to a second aspect, the invention provides a vessel, in particular a cable barge, comprising the aforementioned handling system, wherein the vessel comprises a hull with a bow, a stern and a port side and a starboard side extending in a longitudinal direction between the bow and the stern, wherein the hull defines an elongated storage compartment. The vessel includes the aforementioned handling system and thus has the same advantageous effects, which will not be repeated hereafter for reasons of conciseness.

In an embodiment thereof the loop-shaped laying path comprises a first straight section extending parallel to the longitudinal direction along the port side, a second straight section extending parallel to the longitudinal direction along the starboard side and a first corner section and a second corner section connecting the first straight section to the second straight section at the bow and the stern, respectively, of the vessel.

In an embodiment thereof the laying device comprises a base and a head that is rotatable with respect to said base about a vertical rotation axis, wherein the rotation axis is located at the center between the first straight section and the second straight section. By having the rotation axis at said center location, the laying device can be easily rotated between the first straight section and the second straight section.

In a further embodiment thereof the first corner section and the second corner section are semicircular arcs. Hence, when rotating the head about the rotation axis, the output member can accurately follow the semicircular arcs at the respective corner sections.

In a further embodiment thereof the first straight section and the second straight section extend over at least fifty meters. Hence, a considerable length of the long-length cable can be stored along each straight section.

In a further embodiment thereof the storage compartment comprises a bottom wall that defines a support plane for receiving the long-length cable in a plurality of side-by-side windings along the loop-shaped laying path, a first circumferential wall and a second circumferential wall upright from said bottom wall and extending on the outside and the inside, respectively, of the loop-shaped laying path, to define a first loop-shaped storage chamber for containing said plurality of side-by-side windings along the loop-shaped laying path. Said first storage chamber can be used to securely store the windings of the long-length cable while keeping the central area of the storage compartment free from said windings .

In an embodiment thereof the first circumferential wall and the second circumferential wall have a height with respect to the support plane of at least three meters and preferably at least four meters for receiving a plurality of layers of side-by-side windings of the long-length cable within said height . The higher the circumferential walls, the higher the capacity of the first storage chamber.

In a further embodiment thereof the first loop- shaped storage chamber is wider at the bottom than at the top. Hence, more windings of the long-length cable can be stored towards the bottom. This increases the capacity of the first storage chamber. By increasing the width of the first storage chamber towards the bottom, the stability of the vessel can be ensured.

In a further embodiment thereof the storage compartment comprises a third circumferential wall spaced apart from and extending on the inside of the second circumferential wall to define a second loop-shaped storage chamber. Said second storage chamber can be used to store a second long-length cable within the same vessel.

In a further embodiment thereof the input member is arranged for receiving the long-length cable onto the vessel on the outside of the first circumferential wall, wherein the input member comprises an underpass extending from above the support plane at the outside of the first circumferential wall, underneath the support plane between the first circumferential wall and the second circumferential wall to above the support plane at the inside of the second circumferential wall, wherein the input member is arranged to convey the long-length cable through said underpass into the storage compartment. Said underpass allows the long-length cable to be fed into the storage compartment below the support plane, and thus without hindering the storage of the windings of the long- length cable in the first storage chamber.

According to a third aspect, the invention provides a method for handling a long-length cable on the aforementioned vessel, wherein the method comprises the steps of:

receiving the long-length cable onto the vessel through the input member and feeding the long-length cable with the input member into the storage compartment at an input position;

- moving the laying device along the loop- shaped laying path through the storage compartment while using the output member to lay the long-length cable inside the storage compartment at the output position, wherein said output position moves along said loop-shaped laying path when the laying device is moved;

using the first cable guide for accumulating a length of the long-length cable between the input position and the output position and guiding said accumulated length of the long-length cable along the first guide path; and

variably shaping said first guide path to keep the length of the long-length cable between the input position and the output position constant or substantially constant .

The method describes the active operation of the previously discussed handling system on the previously discussed vessel. Hence, the method has the same advantageous effects as described before. These advantages will not be repeated hereafter for reasons of conciseness.

In a preferred embodiment the method comprises the step of moving the laying device along the loop-shaped laying path at a laying speed, wherein the laying device comprises a pulling member for pulling the long-length cable through the laying device towards the output member at a pulling speed, wherein the method further comprises the step of controlling the pulling speed to a speed smaller than the laying speed during inside-out laying of the long-length cable.

Preferably, the method further comprises the step of controlling the pulling speed to a speed larger than the laying speed during outside-in laying of the long-length cable.

The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, in particular the aspects and features described in the attached dependent claims, can be made subject of divisional patent applications .

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of an exemplary embodiment shown in the attached schematic drawings, in which:

figure 1 shows an isometric view of cable factory and a vessel, in particular a cable barge, moored in the vicinity of said cable factory, wherein the vessel is provided with a handling system according to a first embodiment of the invention;

figure 2 shows the vessel and the handling system of figure 1 in more detail;

figures 3 and 4 shows top views of the handling system in operation during inside-out winding of a long- length cable on said vessel;

figure 5 shows a top view of the handling system in operation during outside-in winding of a long-length cable on said vessel;

figures 6 and 7 show cross sections of the vessel along the lines VI-VI and VII-VII in figures 3 and 4, respectively;

figure 8 shows a cross section of the vessel along the line VIII-VIII in figure 3;

figure 9 shows a cross section of an alternative vessel and an alternative handling system according to a second embodiment of the invention;

figure 10 shows a side view of a part of the handling system in an inactive transport position; and

figure 11 shows a further alternative vessel according to a second embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a cable factory 1 for producing a long-length cable 9 and a vessel 2, in particular a cable barge, moored in the vicinity of said cable factory 1 for receiving and storing the long-length cable 9 from the cable factory 1 for transport. A long-length cable is a cable with a continuous length of at least ten kilometers, preferably at least fifty kilometers and most preferably at least one-hundred kilometers and a weight of more than 500 metric Ton for a single cable. Said long-length cable 9 is typically intended for use in electrical infrastructure, e.g. in an offshore wind farm. In this example, the cable factory 1 is located inland. Said long-length cable 9 has to be transported in an efficient manner via the waterways from the inland cable factory 1 to a port at sea side where a CLV can take over the cable or temporary land storage is organized. Locks and bridges along the waterways limit the width and height, respectively, of the vessel 2.

As shown in more detail in figure 2, the vessel 2 according to a first embodiment of the invention comprises a hull 20 with a bow 21 and a stern 22. The hull 20 further has a port side 23 and a starboard side 24 extending in a longitudinal direction L between the bow 21 and the stern 22. The hull 20 defines an elongated storage compartment 25 for receiving the long-length cable 9 in a manner that will be described in more detail hereafter. The storage compartment 25 comprises a bottom wall 26 that defines a support plane A, as shown in figures 6 and 7, for supporting the long-length cable 9. As shown in figure 2, the storage compartment 25 is further provided with a first circumferential wall 27 and a second circumferential wall 28 extending upright from said bottom wall 26 to define a first loop-shaped storage chamber 29.

The storage compartment 25 has a width W of at least six meters and a length N of at least fifty meters. In this exemplary embodiment, the circumferential walls 27, 28 have a height H of at least four meters.

The vessel 2 is provided with handling system 3 for handling the long-length cable 9 on said vessel 2. The handling includes loading, storing and unloading of said long-length cable 9. The handling system 3 will first be described in relation to the loading process. It will however be apparent to one skilled in the art that unloading merely involves using the handling system 3 in reverse order.

As shown in figures 2-8, the handling system 3 comprises an input member 30 for receiving the long-length cable 9 onto the vessel 2 and for feeding the long-length cable 9 into the storage compartment 25 at an input position B. The input member 30 is preferably arranged for feeding the long-length cable 9 into the storage compartment 25 at the input position B at a feeding direction F parallel or substantially parallel to the longitudinal direction L of the vessel 2. As shown in figure 2, the input member 30 comprises a beam 31 that is arranged to be placed at the bow 21 or the stern 22 of the vessel 2 and that is arranged to be swivable about an upright or vertical swivel axis S between a first loading orientation (shown in dashed lines) parallel to the feeding direction F, a second loading orientation transverse and/or perpendicular to the feeding direction F any loading orientation therein between. The first loading orientation may be used for loading or unloading in line with the feeding direction F, e.g. to another vessel (not shown) or when the draught of the fully loaded vessel 2 makes it impossible to deliver the long-length cable 9 directly onto the quay.

As best seen in figures 6 and 7, the input member 30 further comprises a dancer roller 32. The long-length cable 9 is fed onto the vessel 2 via the input member 30 at an input speed VI . This input speed VI may not always be constant. By measuring the position of the dancer roller 32, a signal indicative of the input speed VI can be obtained, which can be used by the handling system 3 to adapt the loading and/or unloading speed of the long-length cable 9.

The input member 30 further comprises an input channel 33 for guiding the long-length cable 9 from the beam 31 into the storage compartment 25. The input channel 33 extends from the beam 31 at the bow 21 or the stern 22 of the vessel 2 downwards towards the support plane A of the storage compartment 25, yet still on the outside of the first circumferential wall 27. The input member 30 is provided with an underpass 34 in the input channel 33 that extends from above the support plane A at the outside of the first circumferential wall 27, underneath the support plane A between the first circumferential wall 27 and the second circumferential wall 28 to above the support plane A at the inside of the second circumferential wall 28. By having said underpass 34, the long-length cable 9 can be conveyed at least partially underneath the support plane A at the first storage chamber 29 into the part of the storage compartment 25 inside the second circumferential wall 28. The input channel 33 continues downstream of the underpass 34 in the feeding direction F up to the input position B.

As shown in figures 3, 4 and 5, the handling system 3 further comprises a laying device 4 that is arranged for receiving the long-length cable 9 from the input member 30 and for laying the long-length cable 9 in a plurality of windings along a loop-shaped laying path P inside the first storage chamber 29. In particular, the laying device 4 is movable through the first storage chamber 29 along said loop-shaped laying path P in a first laying direction Dl parallel to the longitudinal direction L along the port side 23 and in a second laying direction D2 opposite to the first laying direction Dl along the starboard side 24. The laying device 4 is arranged to be moved along the loop-shaped laying path P at a laying speed V2 that is equal or substantially equal to the input speed VI.

The loop-shaped laying path P comprises a first straight section PI extending parallel to the longitudinal direction L along the port side 23, a second straight section P2 extending parallel to the longitudinal direction L along the starboard side 24 and a first corner section P3 and a second corner section P4 connecting the first straight section PI to the second straight section P2 at the bow 21 and the stern 22, respectively, of the vessel 2. The first corner section P3 and the second corner section P4 are semicircular or one-hundred-and-eighty degree arcs. The first straight section PI and the second straight section P2 preferably extend over at least fifty meters, most preferably over at least seventy-five meters. Hence, the long-length cable 9 can be wound inside the storage chamber 25 along the loop-shaped laying path P with relatively long windings extending straight along a substantial part of the port side 23 and the starboard side 24 of the vessel 2. In particular, each winding may store a length of the long-length cable 9 of at least one-hundred meters, preferably at least two-hundred meters and most preferably at least two-hundred-and-fifty meters.

As best seen in figure 8, the laying device 4 comprises a base 40 and a head 41 that is rotatable with respect to said base 40 about an upright or vertical rotation axis R. The laying device 4 is provided with an output member 42 at the head 41 for laying the long-length cable 9 in the storage compartment 25 along the loop-shaped laying path P. The head 41 is arranged to be rotated about the rotation axis R when transitioning from the first laying direction Dl to the second laying direction D2 at the first corner section P3 between figures 3 and 4 and when transitioning from the second laying direction D2 to the first laying direction Dl at the second corner section P4. During said rotation, the head 41 is rotated over one- hundred-and-eighty degrees to move the output member 42 from one straight section PI, P2 to the other straight section PI, P2 at the respective corner section P3, P4 while the output member 42 follows the loop-shaped laying path P.

As best seen in figure 8, the output member 42 comprises a laying arm 43 with an output nozzle 44 at the distal end thereof to lay the long-length cable 9 into the storage compartment 25 along the loop-shaped laying path P. The laying arm 43 has an arc that allows for tangentially laying the long-length cable 9 into the storage compartment 25, parallel to the support plane A. The laying arm 43 is swivable about a laying axis T for adjusting the output position B laterally with respect to the loop-shaped laying path P with each winding, e.g. in a direction towards or away from the center of the storage compartment 25. In particular, during inside-out laying of the long-length cable 9, the laying arm 43 is swiveled about the laying axis T from the second circumferential wall 28 towards the first circumferential wall 27 with increments that correspond to the thickness of the long-length cable 9. Similarly, during outside-in laying of the long-length cable 9, the laying arm 43 is swiveled about the laying axis T from the first circumferential wall 27 towards the second circumferential wall 28 with similar increments. In this manner, the long-length cable 9 can be accurately laid into the storage compartment 25 in stacked layers of side- by-side windings.

To facilitate the stacking of the layers, as shown in figure 8, the head 41 is liftable with respect to the base 40 in a lifting direction Y parallel to the rotation axis R, e.g. with the use of pistons. After a layer has been completed, the head 41 is lifted over a distance that is equal to the thickness of a layer to stack another layer on top of the previously completed layer. The head 41 is liftable to such an extent that the full height H of the first storage compartment 29 between the first circumferential wall 27 and the second circumferential wall 28 can be filled, thereby fully utilizing the capacity of the first storage chamber 29.

As shown in figures 6 and 7, the handling system

3 comprises a first cable guide 6 for accumulating a length of the long-length cable 9 between the input position B and the output position C. The first cable guide 6 is arranged for guiding said accumulated length along a first guide path that is variable in shape to keep the length between the input position B and the output position C constant or substantially constant. More in particular, the first cable guide 6 is arranged for doubling back at least a part of the accumulated length of the long-length cable 9 in a return direction E opposite to the feeding direction F when the laying device 4 is upstream of the input position B in the feeding direction F. The input position B is preferably located half-way along the loop-shaped laying path P in the feeding direction F. Hence, the accumulated length of the long-length cable 9 can be doubled back along at least half of the loop-shaped laying path P.

Note that while the first cable guide 6 accumulates a constant length of the long-length cable 9, said long-length cable 9 is continuously fed via the input member 30 at the input speed VI through the input position B, through the first cable guide 6 along the first guide path, through the laying device 4 and out of the output member 42 at the output position C into the first storage chamber 29. Hence, although the accumulated length of the long-length cable 9 may be kept constant, the long-length cable 9 itself is continuously moving relative to the first cable guide 6.

The first cable guide 6 comprises a plurality of interlinked segments 60 that are movable with respect to each other to define the first guide path. Preferably, the first cable guide 6 is a cable carrier, preferably a chain- style cable carrier. The interlinked segments 60 have a limited freedom of rotation with respect to each other, so that the interlinked segments 60 can only form an arc with a minimum radius of at least two meters. This can prevent that the long-length cable 9 is bend beyond its minimum bending radius.

The first cable guide 6 is arranged for forming a first variably arcuate section 61 in the first guide path. Said first variably arcuate section 61 is arranged for directing the long-length cable 9 from the feeding direction F into a first guide direction Kl towards the laying device 4. The first variably arcuate section 61 can be shaped and/or rolled-up into an arc of up to one- hundred-and-eighty degrees such that the first guide direction Kl is opposite to the feeding direction F. As best seen in figure 7, the handling system 3 is provided with a plurality of guide supports 65 for supporting the first cable guide 6, preferably at regular intervals, with respect to the vessel 2 when a considerable part of the accumulated length of the long-length cable 9 is doubled back in said first guide direction Kl. Hence, the weight of the first cable guide 6 and the long-length cable 9 carried therein can be reliably supported along the entire first guide path.

As shown in figure 6 and 7, the laying device 4 is provided with a second cable guide 7 at the head 41 that is arranged for receiving the long-length cable 9 from the first cable guide 6 in a second guide direction K2 along a second guide path into a third guide direction K3 towards the output member 42. The second cable guide 7 rotates together with the head 41 about the upright or vertical rotation axis R to direct the long-length cable 9 towards the output member 42 as the laying device 4 is moved along the loop-shaped laying path P. As best seen in figure 8, the second guide direction K2 is directed away from the output member 42. In this exemplary embodiment, the laying device 4 is arranged to extend upright or vertical from the storage compartment 25. As such, the second guide direction K2 is upwards and the third guide direction K3 is downwards . The second cable guide 7 extends over an arc of at least one-hundred-and-eighty degrees from the upward second guide direction K2 to the downward third guide direction K3.

The second guide direction K2 is different from the first guide direction Kl defined by the first variably arcuate section 61 of the first cable guide 6. The first cable guide 6 is therefore arranged for forming a second variably arcuate section 62 in the first guide path that is arranged for directing the long-length cable 9 from first guide direction Kl into said second guide direction K2 towards and into the laying device 4. Hence, the long- length cable 9 can be fed tangentially from the input position B through the first guide member 6 into the second guide member 7.

Like the first cable guide 6, the second cable guide 7 comprises a plurality of interlinked segments 70 that are movable with respect to each other to define the second guide path. Preferably, the second cable guide 7 is a cable carrier, preferably a chain-style cable carrier. The interlinked segments 70 have a limited freedom of rotation with respect to each other, so that the interlinked segments 70 can only form an arc with a minimum radius of at least two meters. This can prevent that the long-length cable 9 is bend beyond its minimum bending radius.

In figures 6, 7 and 8, the laying device 4 is shown in an active upright position in which a considerable part of the laying device 4 extends above and/or protrudes upwards from the storage compartment 25 to above the deck of the vessel 2. In this active upright position, the vessel 2 may not be able to pass under some lower bridges. Hence, the head 41 is foldable with respect to the base 40 member about a horizontal folding axis M from the active upright position, as shown in figures 6, 7 and 8, into an inactive transport position as shown in figure 10. The folding axis M may extend parallel to the feeding direction F, in which case the head 41 is folded down in a lateral direction with respect to the longitudinal direction L of the vessel 2, or perpendicular to the feeding direction F, in which case the head 41 is folded down in the longitudinal direction L.

As shown in figure 8, the laying device 4 further comprises a pulling member 45 for pulling the long-length cable 9 through the laying device 4 towards the output member 42 at a pulling speed V3. The handling system 3 comprises a control unit 8 for controlling the pulling speed V3 of the pulling member 45. In particular, the control unit 8 is arranged for controlling the laying speed V2 and/or the pulling speed V3 such that the pulling speed V3 is smaller than the laying speed V2 during inside-out laying of the long-length cable 9 to pull consecutive windings of the long-length cable 9 tightly against each other, in particular at the corner sections P3, P4 of the loop-shaped laying path P. Similarly, the control unit 8 is arranged for controlling the laying speed V2 and/or the pulling speed V3 such that the pulling speed V3 is larger than the laying speed VI during outside-in laying of the long-length cable 9 to push consecutive windings of the long-length cable 9 tightly against each other, in particular at the corner sections P3, P4 of the loop-shaped laying path P.

A method for handling a long-length cable 9 on the previously discussed vessel 2, using the aforementioned handling system 3, will be elucidated below with reference to figures 1-8.

Figure 1 shows the situation in which the long- length cable 9 is being manufactured in the factory 1 and is subsequently fed by a feeding system from the factory 1 to the vessel 2. At the vessel 2, the input member 30 of the handling system 3 receives the long-length cable 9 from the factory 1 and guides it into the storage compartment 25 of the vessel 2 in the manner as described before.

As shown in figures 3 and 6, the long-length cable 9 is fed by the input member 30 into the storage compartment 25 at input position B. In figure 3, the situation is shown in which the laying device 4 has already laid two windings of the long-length cable 9 into the first storage compartment 29 along the loop-shaped storage path P and has started to lay a third winding of the long-length cable 9 on the outside of the previously laid windings of the same long-length cable 9. In figure 3, the laying device 4 has just moved through the second corner section P4 of the loop-shaped laying path P and is now ready to move at the laying speed V2 in the first laying direction Dl along the first straight section PI at the portside 23 of the vessel 2. As the laying device 4 moves in the first laying direction Dl towards and beyond the input position B, the first cable guide 6 doubles back the long-length cable 9 in the return direction R opposite to the feeding direction F to keep the accumulated length of the long- length cable 9 between the stationary input position B and the continuously moving output position C constant.

Figures 4 and 7 shows the situation in which the laying device 4 has completed laying the third winding of the long-length cable 9. The head 41 of the laying device 4 has been rotated about the rotation axis R through the first corner section P3 and is now ready to move in the second laying direction D2 along the second straight section P2 at the starboard side 24 of the vessel 3. The doubled back length of the long-length cable 9 in the first cable guide 6 is now gradually rolled back in the feeding direction F, again to keep the accumulated length of the long-length cable 9 between the stationary input position B and the continuously moving output position C constant.

Figure 5 shows the situation after a first layer of windings of the long-length cable 9 has been completed and the laying device 4 has started a new layer of windings of the long-length cable 9 on top of the previously completed windings. For this purpose, the laying device 4 has been lifted in the lifting direction Y as shown in figure 7. This process can be continued until the first storage chamber 29 is completely filled.

Figure 9 shows an alternative vessel 102 according to a second embodiment of the invention. The alternative vessel 102 differs from the previously discussed vessel 2 in that the circumferential walls 127, 128 that form the first storage compartment 129 are not parallel. Instead, they are spaced apart further at near the bottom wall 126 than at the top. Hence, the alternative first storage chamber 129 is wider at or near the bottom wall 126 than at the top. This allows for more side-by-side windings of the long-length cable 9 towards the bottom, thereby increasing the capacity of the first storage chamber 129.

Figure 9 further shows an alternative handling system 103 according to a second embodiment of the invention that can be applied individually or together with the aforementioned alternative first storage compartment 129. The alternative handling system 103 differs from the previously discussed handling system 3 in that the second cable guide 107 of the laying device 104 follows a second guide path that includes a freefall section 171 directly upstream of the output member 140. In said freefall section 171 the second guide path extends vertical or substantially vertical, preferably over at least three meters, most preferably over at least five meters, to allow the long- length cable 9 to relax tension, e.g. torsion and/or twists in the long-length cable 9 prior to the laying at the output position C.

Figure 11 shows a further alternative vessel 202 according to a third embodiment of the invention. The further alternative vessel 202 differs from the vessel 2 according to the first embodiment of the invention only in that it is provided with a third circumferential wall 228 in the storage compartment 25. Said third circumferential wall 228 is spaced apart from and extending on the inside of the second circumferential wall 28 to define a second loop-shaped storage chamber 229 extending along an alternative loop-shaped laying path Z adjacent to loop- shaped laying path P in the first loop-shaped storage chamber 29. The second loop-shaped storage chamber 229 can be used to store an additional long-length cable (not shown) . The radius of said second storage chamber 229 is slightly smaller than the radius of the first storage chamber 29 at the corner sections P3, P4. Hence, the second storage chamber 229 would probably be used for thinner cables that can bend to smaller radii.

The vessel 2 may comprises means for performing post-loading tests, such as time domain reflector (TDR) and/or optical time domain reflector (OTDR) measurements on the loaded long-length cable 9. The vessel 2 may further comprises electronic means to further measure, log and/or control various parameters, such as - but not limited to - input speed VI, pulling speed V2, laying speed V3, temperature and acceleration or deceleration of the vessel 2 as a whole.

It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention.

In summary, the invention relates to a handling system, a vessel and a method for handling a cable on said vessel. The vessel comprises a hull that defines an elongated storage compartment . The handling system comprises an input member for receiving the cable onto the vessel and for feeding the cable into the storage compartment at an input position, a laying device that is movable along a loop-shaped laying path, an output member that is arranged for laying the cable inside the storage compartment at an output position and a first cable guide for accumulating a length of the cable between the input position and the output position, wherein the first cable guide is arranged for guiding said accumulated length of the cable along a first guide path that is variable in shape to keep the length of the cable between the input position and the output position constant or substantially constant .